GILLETTE, Wyo. (AP) – Two bats from northeastern Wyoming's Devils Tower National Monument have been found with the state's first confirmed cases of a deadly fungal disease.

White-nose syndrome has killed millions of bats in North America since the fungus first appeared in New York in 2006.

Testing showed signs of the fungus in bats from southeastern Wyoming in 2018. The recent confirmation at Devils Tower, the first U.S. national monument, is “disheartening and frustrating,” park resources management chief Russ Cash said.

“Bats are such an important piece of our ecosystem and our well-being as humans. Bats devour unbelievable amounts of insects and pests that are a nuisance,” Cash said in a statement Tuesday.

The positive test results were no surprise. Biologists confirmed the disease in the Black Hills in South Dakota in 2018 and a dead bat in southeastern Montana’s Fallon County in April, the Gillette News Record reports.

The disease has appeared in at least 37 states and seven Canadian provinces.

The fungus spreads mainly between bats but climbers and cavers can spread it too. They should clean and disinfect shoes, clothes and gear before and after visiting bat habitat and avoid reusing potentially exposed items in places free of the fungus, National Park Service officials said.